Exhaust decoupler

ABSTRACT

A decoupler of an exhaust pipe having spaces for absorbing various stresses caused by impact, vibration, heat distortion, or the like. The decoupler includes a corrugated bellows repeatedly formed with corrugations, a sleeve for protecting the bellows against exhaust gas, an outer cap for enclosing the outer side of one end of the bellows, an inner cap for enclosing the outside of the bellows, and wire mesh buffering members installed in spaces defined by the inner cap and the outer cap, to support the inner cap and the outer cap and to maintain air tightness between the inner cap and the outer cap. The outer cap has bending portions formed at the ends thereof, so as to maintain a gap between the outer surface of the inner cap and the end of the outer cap. The surfaces of the buffering members are closely attached to the outer surface of the inner cap, upper inside surfaces of the bending portions and lateral inner surfaces of the bending portions, so as to define buffering spaces between the buffering members and the bending portions. Thus, the deformation of the decoupler can be prevented so as to reduce wearing of the decoupler and frictional noise and to enhance the durability of the decoupler.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a decoupler of an exhaust pipe, andmore particularly to a decoupler including a bellows having one endcoupled between a sleeve and an outer cap, the other end coupled to theinner circumferential surface of an inner cap, side corrugationsconnected to the outer cap and the inner cap and smaller than a middlecorrugation so as to form a rounded overall shape of the bellows, theinner cap formed with curved surfaces corresponding to the overall shapeof the bellows, the outer cap formed with bending portions so as to havecorners, buffering members supported by the curved surfaces of the innercap and the inner surfaces of the bending portions of the outer cap, andspaces formed in the insides of the bending portions, so that variousstresses due to impact, vibration, and heat distortion, are absorbed bythe spaces, and the deformation of the decoupler can be prevented.

2. Description of the Related Art

Generally, a vehicle engine is connected with an exhaust pipe having amuffler to exhaust the exhaust gas. At the connection point of theexhaust pipe is installed a decoupler, as a connecting device. Thedecoupler prevents vibration from being transmitted to the vehicle bodyby absorbing vibration caused by explosions in the engine, and preventsexternal shock from being transmitted to the engine. Moreover, thedecoupler absorbs displacement caused by vibration and impact load andbuffers heat distortion. The decoupler includes a bellows, a sleeve, anouter cap for enclosing the outside of the bellows, and an inner cap.The bellows has a plurality of corrugations and is disposed between anengine and the exhaust pipe coupled to the vehicle body. The sleeve isinserted into one side of the bellows to be connected to the engine. Theinner cap is disposed between the bellows and the outer cap, and isspaced from the outer cap.

The decoupler constructed as described above prevents vibration frombeing transmitted to the vehicle body by absorbing the vibrationgenerated from the engine, and prevents vibration generated from thevehicle body due to uneven road conditions from being transmitted to theengine, so as to protect the engine. The decoupler must absorb thevibration and displacement generated at the exhaust system of thevehicle. Stress and displacement absorbed by the decoupler may includevarious stresses, such as tensile stress, compressive stress, bendingstress, and torsional stress, and excessive displacement generated inevery direction.

The decoupler includes a bellows disposed between rims and a bufferingmember, for enclosing the outer surface of the engine. The rims and thebuffering members absorb vibration of the engine, the expansiondisplacement in the longitudinal direction generated by impact when inmotion, and bending displacement when the central axes of exhaustconnecting devices are deviated from each other. Since the inner capcoupled to the engine is separated from the outer cap coupled to theexhaust pipe, the buffering member and the bellows are formed withrespective elastic portions. The elastic portions are disposed betweenthe inner cap and the outer cap and support the inner cap and the outercap, so as to absorb the deformation, vibration, and impact stress.

Therefore, in the decoupler, it is very important that the bellows and awire mesh, of which one end is connected to the engine and the other endis connected to the exhaust pipe, allow the exhaust gas to flow througha central part thereof, and are expanded to absorb the impact and thedeformation generated between the engine and the exhaust pipe.

To overcome the above-described disadvantage, extensive research and avariety of approaches have been proposed. A conventional decoupler forconnecting an exhaust pipe to an engine, as shown in FIG. 1, includes asleeve 20 coupled to the engine 200, a bellows coupled to an outersurface of one end of the sleeve 20 which is coupled to the engine 200,an outer cap 20 installed outside the bellows 10, an inner cap 40disposed between the outer cap 30 and the bellows 30 and integrallyconnected to the other end of the bellows 10, in which the exhaust pipe300 is coupled, and supporting wire meshes 500 filled in a space on oneend 31 of the outer cap 30, defined by the outer cap 30 and the innercap 40, and a space on one end 41 of the inner cap 40, defined by theouter cap 30 and the inner cap 40.

However, the above-mentioned decoupler does not sufficiently manageimpact, vibration, and heat distortion, and is not flexible because ofthe deformation of the inner cap 40 and/or the outer cap 30, so that thedecoupler cannot fulfill its designed functions.

The development of the above-described decoupler is shown in FIG. 2. Asshown in FIG. 2, the development of the decoupler includes a sleeve 20coupled to the engine 200, a bellows coupled to an outer surface of oneend of the sleeve 20 which is coupled to the engine 200, an outer cap 20installed outside the bellows 10, an inner cap 40 disposed between theouter cap 30 and the bellows 30 and integrally connected to the otherend of the bellows 10, to which the exhaust pipe 300 is coupled,supporting wire meshes 500 filled in a space on one end of the outer cap30, defined by the outer cap 30 and the inner cap 40, and a space on oneend of the inner cap 40, defined by the outer cap 30 and the inner cap40, and shock-absorbing wire meshes 600 filled the outside spaces of thesupporting wire meshes 500, defined between the supporting wire meshes500. However, the above-mentioned decoupler, does not sufficientlymanage impact, vibration, and heat distortion, and is not flexiblebecause of the deformation of the inner cap 40 and/or the outer cap 30,so that the decoupler cannot fulfill its designed functions.

SUMMARY OF THE INVENTION

Therefore, the present invention has been made in view of the aboveproblems, and it is an object of the present invention to provide adecoupler including a bellows having one end coupled between a sleeveand an outer cap, the other end coupled to the inner circumferentialsurface of an inner cap, side corrugations connected to the outer capand the inner cap and smaller than a middle corrugation, to form arounded whole shape of the bellows, the inner cap formed with curvedsurfaces corresponding to the rounded overall shape of the bellows, theouter cap formed with bending portions to have corners, bufferingmembers supported by the curved surfaces of the inner cap and the innersurfaces of the bending portions of the outer cap, and spaces formed inthe insides of the bending portions, so that various stresses due toimpact, vibration, and heat distortion, are absorbed by the spaces.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other objects and advantages of the present invention willbecome apparent and more readily appreciated from the followingdescription of the embodiments, taken in conjunction with theaccompanying drawings, in which:

FIG. 1 is a cross-sectional view of a conventional decoupler;

FIG. 2 is a cross-sectional view of another conventional decoupler;

FIG. 3 is a partial cross-sectional view of a decoupler according to thepresent invention; and

FIG. 4 is a schematic view illustrating installation of the decoupleraccording to the present invention and the conventional decoupler to thevehicle engine.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, a decoupler according to the present invention will bedescribed in connection with the accompanying drawings.

As shown in FIG. 3, the decoupler includes a corrugated bellows 10, asleeve 20, an outer cap 30, an inner cap 40, and buffering members 50made of wire meshes.

The corrugated bellows 10 is formed with repeated wave-formedcorrugations. The sleeve 20 is inserted into the bellows 10 and protectsthe bellows 10 against exhaust gas. The sleeve 20 has one end with alarge diameter fixed to an inner surface of one end of the bellows 10,and a free end of a small diameter spaced apart from an inner surface ofthe bellows 10.

The outer cap 30 encloses the outer side of one end of the bellows 10where the sleeve 20 is coupled. The inner cap 40 is installed betweenthe outer cap 30 and the bellows 10, and is also coupled to the otherend of the bellows 10, so as to enclose the outside of the bellows 10.

The buffering members 50 are installed in a space on one end of theinner cap 40, defined between an outer surface of the inner cap 40 andan inner surface of the outer cap 30, and in a space on one end of theouter cap 30, defined between the outer surface of the inner cap 40 andthe inner surface the outer cap 30, so as to support the inner cap 40and the outer cap 30 and to maintain air tightness between the inner cap40 and the outer cap 30.

The corrugations 11 formed at sides of the bellows 10 are smaller thancorrugations 12 formed at a middle portion of the bellows 10. Thus thebellows forms a gentle curved line R.

The inner cap 40 has curved surfaces 45 respectively formed at a leadingend and the other end thereof, so that the curved surfaces of the innercap 40 correspond to the curved line formed by the corrugations 11 and12 of the bellows 10. The inner cap 40 encloses surfaces of thecorrugations 11 and 12 to be adjacent to the surfaces of thecorrugations 11 and 12 of the bellows 10.

However, it is very important that the inner cap 40 does not interferewith the bellows 10.

The outer cap 30 has L-shaped cross-sectional bending portions 35respectively formed at the end 31 of the outer cap 30 and at a portioncorresponding to the end 41 of the inner cap 40, and the end 31 of theouter cap 30 has an inner diameter sufficient to be spaced apart from anouter circumference of the inner cap 40, so as to maintain a gap betweenthe outer surface of the inner cap 40 and the end of the outer cap 30.Thus, the outer cap 30 properly manages the tensile stress and thebending stress.

The lower surfaces 51 of the buffering members 50 are closely attachedto an outer curved surface of the inner cap 40, upper surfaces 52 of thebuffering members 50 are closely attached to upper inside surfaces ofthe bending portions 35 and lateral surfaces 53 of the buffering members50 are closely attached to lateral inner surfaces of the bendingportions, so as to define buffering spaces 60 between the bufferingmembers 50 and the bending portions 35.

Reference numeral 200 indicates the vehicle engine, and referencenumeral 300 indicates the exhaust pipe of the vehicle having themuffler.

When the decoupler according to the present invention will be used bybeing installed to the vehicle engine 200, as shown in FIG. 4, there mayappear various situations caused by road conditions in the traveling andheat distortion due to the heat of the exhaust gas generated from theengine 200. Here, the effect of the decoupler according to the presentinvention will be described by using some situations as examples.

The sleeve 20 having a free end is the first to absorb the heatgenerated from the exhaust gas, the rest of the heat is transmitted tothe bellows 10. The corrugations of the bellows 10 absorb stress causedby the heat as much as possible. Moreover, the bellows 10 absorbs thevibration due to the explorations in the engine 200 so as to prevent thevibration from being transmitted to the exhaust pipe 300.

In this state, when various stresses, such as vibration, bending stress,tensile stress, and the like, generated from wheels of the vehicle whenin motion are transmitted to the decoupler via the exhaust pipe 300, thebending stress and the torsional stress are absorbed by the deformationand restoration of the bellows 10 by which the wire mesh bufferingmembers 50, disposed between the outer cap 30 and the inner cap 40, areslid over the outer surface of the inner cap 40. The tensile stress andthe impact stress are absorbed in a manner that the wire mesh bufferingmembers 50, disposed between the inner cap 40 and the outer cap 30, aredeformed and restored in the spaces 60 defined between the outer cap 30and the bending portions 35.

As described above, the bellows 10 is installed such that one end of thebellows 10 is coupled between the sleeve 20 and the outer cap 30 and theother end of the bellows 10 is coupled to the inner circumferentialsurface of the inner cap 40. The bellows 10 has the side corrugations11, connected to the outer cap 30 and the inner cap 40, smaller than themiddle corrugation 12, so as to form a rounded overall shape. The innercap 40 is formed with the curved surfaces 45 corresponding to theoverall shape of the bellows 10. The outer cap 30 is formed with thebending portions 35 so as to have corners. The buffering members 50 aresupported by the curved surfaces 45 of the inner cap 40 and the innersurfaces of the bending portions 35 of the outer cap 30. The spaces 60are formed in the insides of the bending portions 35, so that variousstresses due to impact, vibration, and heat distortion, are absorbed inthe spaces 60. Thus, the deformation of the decoupler can be preventedso as to reduce wearing of the decoupler and frictional noise and toenhance the durability of the decoupler.

Although the preferred embodiments of the present invention have beendisclosed for illustrative purposes, those skilled in the art willappreciate that various modifications, additions and substitutions arepossible, without departing from the scope and spirit of the inventionas disclosed in the accompanying claims.

1. An exhaust decoupler for an engine comprising: a corrugated bellowsformed with wave-formed corrugation repeatedly; a sleeve, inserted intothe bellows, for protecting the bellows against exhaust gas, having oneend with a large diameter fixed to an inner surface of one end of thebellows, and a free end of a small diameter spaced apart from an innersurface of the bellows; an outer cap for enclosing the outer side of oneend of the bellows where the sleeve is coupled; an inner cap, installedbetween the outer cap and the bellows, and coupled to the other end ofthe bellows, for enclosing the outside of the bellows; and wire meshbuffering members, installed in a space on one end of the inner cap,defined between an outer surface of the inner cap and an inner surfaceof the outer cap, and in a space on one end of the outer cap, definedbetween the outer surface of the inner cap and the inner surface of theouter cap, for supporting the inner cap and the outer cap andmaintaining air tightness between the inner cap and the outer cap,wherein corrugations formed at sides of the bellows are smaller thancorrugations formed at a middle portion of the bellows, so as to form agentle-curved-line-shaped bellows, the outer cap has L-shapedcross-sectional bending portions respectively formed at the end of outercap and a portion corresponding to the end of the inner cap, and the endof the outer cap has an inner diameter sufficient to be spaced apartfrom an outer diameter of the inner cap, so as to maintain a gap betweenthe outer surface of the inner cap and the end of the outer cap, andlower surfaces of the buffering members are closely attached to an outercurved surface of the inner cap, upper surfaces of the buffering membersare closely attached to upper inside surfaces of the bending portionsand lateral surfaces of the buffering members are closely attached tolateral inner surfaces of the bending portions, so as to definebuffering spaces between the buffering members and the bending portions.